The Fred Hutchinson Cancer Research Center (FHCRC) is a NCI Comprehensive Cancer Center which was admitted as a Special Member of Children's Cancer Group (CCG) in November, 1991 based on FHCRC's expertise in marrow transplantation. The primary mission of FHCRC is to improve the depth of understanding of cancer through basic, epidemiologic and clinical research. The unique clinical research facility is dedicated primarily to the general topic of marrow transplantation as a modality to cure hematologic malignancies. All patients treated at FHCRC are referred at a time when marrow transplantation is the indicated form of therapy. The 12- 31 patients referred from CCG institutions for marrow transplantation according to CCG protocols are transplanted according to the appropriate CCG protocol. All other patients (approximately 400 each year) are transplanted according to local FHCRC protocols. These protocols, generated by the major programs in the Clinical Research Division, address issues of preventing recurrence of leukemia after allogeneic or autologous marrow transplant, prophylaxis or treatment of graft versus host disease and development of immunologic tolerance, prevention of infections in immunocompromised patients, evaluations of the genetics of antigens governing tissue compatibility, development of monoclonal antibodies for treatment of leukemia, and studies defining and treating late effects after transplant. New programs are being developed to evaluate adoptive immunotherapy involving gene insertion therapy for specific hematologic malignancies and solid tumors. The results from the various programs of FHCRC have been of direct and indirect benefit to current CCG prospective studies incorporating marrow transplantation as part of treatment plan and will no doubt influence future CCG marrow transplant studies as well.